1. Technical Field
The present invention relates to yeast which is ethanol resistant and contains the high content of organic bio-germanium, and the method for producing the yeast. More specifically, the method comprises producing a mutated Saccharomyces cervisiae, i.e., yeast GP-01 by protoplast fusion of Saccharomyces cervisiae (KCTC7904) and candida ethanolica (KCTC7181), the yeast being resistant against the high concentrate ethanol; cultivating the yeast GP-01 with sodium metagermanate (Na2GeO3) for germanium to be inoculated into the yeast GP-01 by the biotransformation; and finally obtaining a mutated yeast being ethanol-resistant and containing the high content of organic bio-germanium (hereinafter referred to as the yeast Ge-32K).
2. Background Art
Germanium is classified with organic and inorganic germanium (GeO2). It is known the inorganic germanium accumulated in the human organs over the long time leads to the strong toxicity.
Organic germanium is naturally contained in microorganisms, mineral water and medicinal herbs. Further, it can be bio-synthesized in the fungal body or chemically synthesized. The organic germanium is organically bound to the proteins in the cell, peptides, etc. and the therapeutic benefits of the organic germanium for enhancing immunity; suppressing the origination and spread of the tumor cells (metastasis), treating and preventing various chronic diseases, etc. are established by numerous papers and scientific journals (Kor. J. Microbiol. Biotechnol., 2007. 35(2):118-127; J. Kor. Soc. Food Sci. Nutr. 2006. 35(6):683-689; J. Kor. Soc. Appl. Biol. Chem. 2005.48(3):246-251; Immune Network. 2006. 6(2):86-92). In addition, the organic germanium is well-known for anticancer activities by oxygen supply to cells (J. Orthomol. Medicin., 1986. 1:145-148), purification of blood (Medicin. Hyphothesis., 1988. 26:207-215), reinforcement of immunity by activation of NK cell and macrophage (Microbiol. Immunol., 1985. 29:65-74; Kor. J. Microbiol. Biotechnol., 2007. 35(2):118-127); inducement of interferon production (Gantokagakutyoho, 9:1976-1980); suppression of generating and spreading the cancer cell (Cancer and Chemotheraphy. 1985. 12(12):2345-2351); suppression of arthritis (Autonomic & Autacoid Pharmacol. 2005. 25:129-134); prevention and treatment of various diseases such as neuralgia (Biotechnol. Appl. Biochem., 1986. 8:379-386), osteoporosis (Germanium; The health and life enhancer. 1988); mitigation of high blood pressure (hypertension) and hyperlipidemia cholesterol (Pharmacol., 1990. 41:286-291); alleviation of liver toxin (J. Kor. Soc. Food. Nutr., 1994. 23(4): 581-586); and so forth. Due to the well-known therapeutic benefits, many researches on organic germanium have been widely undertaken for decades in an attempt to apply it for treatment of various obstinate diseases such as cancer and cardiopathy, etc. in U.S.A., Japan, Europe and Korea (Anticancer Res., 1985. 5(5):479-483).
The organic germanium can be obtained by extracting from medicinal herbs like ginseng, ganoderma, etc., but such a method is difficult to be commercialized due to high cost and low productivity. Further, the organic germanium can be obtained by a chemical synthesis which includes a reaction of germanium dioxide (GeO2) with organic acids, but the product obtained from the chemical synthesis comprises the inorganic germanium and thus the use for the foods or medical supplies is limited due to the un-established safety (Import Alert by US FDA, 1988).
In fact, the yeast is importantly used in baking, confectionery and brewery industry for thousands of years. Further, the yeast itself is useful as a source of nutrition for human being and attractive as a next generation protein source, a single cell protein (SCP) which is ideally comprised of protein, vitamin, mineral, etc. and characterized in the high protein and low fat.
Furthermore, the yeast is the best source of Vitamin B among the single cells and comprising lots of enzymes etc., which are mainly served in vivo metabolism. In this respect, the yeast is used as the health supplementary product. Recently, a large number of researches and developments on the health supplement products have been made so that the physiological and pharmaceutical benefits by the yeast are obtained. In order to achieve the said object, the development for the yeast containing the high contents of organic bio-germanium is highly required.
In the conventional methods, the yeast containing the organic bio-germanium is produced by cultivating the yeast in the medium including inorganic germanium (GeO2). Due to the drawback that the growth of yeast is suppressed in the condition of the medium where the high content of the inorganic germanium is contained, it is difficult in the conventional methods to produce the yeast containing the appropriate amount of organic bio-germanium in aspect of the cost-effective and scale.
To remedy the above drawback, a method separately executing the process of producing the yeast in the form of a pellet and the process of inoculating germanium dioxide (GeO2) in the obtained yeast is tried. However, in the above method, the yield of the palletized yeast is too low to be commercialized due to the ethanol generated during the cultivation of yeast and the content of germanium dioxide (GeO2) inoculated into the yeast is extremely low.
Also it has been known that the solubility of germanium dioxide (GeO2) used in the above method is 5.2 g/L at 25° C., which is served as the suppresser of the growth of yeast (J. Ind. Microbiol. Biotechnol., 1989. 4(4):299-306).    1. Therefore, it is highly required to invent the method to produce the ethanol resistant yeast containing the high content of organic bio-germanium by using the inorganic germanium which has higher solubility but much lower toxicity than germanium dioxide (GeO2).